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| Titel |
Distribution of extreme rainfall events over Ebro River basin |
| VerfasserIn |
Antonio Saa, Ana María Tarquis, Jose Luis Valencia, Jose Maria Gasco |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250041320
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| Zusammenfassung |
| The purpose of this work is to provide a description of the heavy rainfall phenomenon on
statistical tools from a Spanish region.
We want to quantify the effect of the climate change to verify the rapidity of its
evolution across the variation of the probability distributions. Our conclusions have
special interest for the agrarian insurances, which may make estimates of costs more
realistically.
In this work, the analysis mainly focuses on:
The distribution of consecutive days without rain for each gauge stations
and season. We estimate density Kernel functions and Generalized Pareto
Distribution (GPD) for a network of station from the Ebro River basin until a
threshold value u. We can establish a relation between distributional parameters
and regional characteristics. Moreover we analyze especially the tail of the
probability distribution. These tails are governed by law of power means that
the number of events n can be expressed as the power of another quantity x :
n(x) = xÏ . Ï can be estimated as the slope of log-log plot the number of events
and the size. The most convenient way to analyze n(x) is using the empirical
probability distribution. Pr(X > x) - x-Ï.
The distribution of rainfall over percentile of order 0.95 from wet days at the
seasonal scale and in a yearly scale with the same treatment of tails than in the
previous section.
The evolution of the distribution in the second XXth century and the impact on
the extreme values model.
After realized the analyses it does not appreciate difference in the distribution throughout the
time which suggests that this region does not appreciate increase of the extreme values both
for the number of dry consecutive days and for the value of the rainfall
References:
Coles, Stuart (2001). An Introduction to Statistical Modeling of Extreme Values,.
Springer-Verlag
Krishnamoorthy K. (2006), Handbook of Statistical Distributions with Applications,
Chapman & Hall/CRC.
Bodini A., Cossu A. (2010). Vulnerability assessment of Central-East Sardinia
(Italy) to extreme rainfall events. Natural Hazards and Earth System Sciences. 61-72 |
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